Chain of events: a blog of Food Chain Intelligence

There is an ongoing debate on the contents of a draft report published by the National Health and Medical Research Council (NHMRC). The authors of this report are the Dietitians Association of Australia, with help from well known nutrition experts such as Dr Katherine Baghurst, Dr Peter Baghurst, Dr Lynne Cobiac and Dr Anthea Magarey.

The goal of the update is to translate the NHMRC Nutrient Reference Values for Australia and New Zealand Including Recommended Dietary Intakes (NRVs) into food consumption patterns that:

a) deliver the nutrient requirements for people of varying age/gender, activity levels and life-stages

b) are culturally acceptable, socially equitable and environmentally sustainable

c) reflect the current Australian food supply and food consumption patterns

d) provide some flexibility in food choice and;

e) promote health and wellbeing.

The approach used in the draft report was to use a mathematical model to optimise diets that theoretically contain all nutrient requirements for the various age, gender, and life stage groups analysed. The target was the least amount of energy (kilojoules, kJ), using  a) to e) as constrains to the model.

Me being a modeller, I think this is a fabulous study that would be better placed as a research article, and not a draft for public consultation.

Why? Because the use of cultural, social and environmental constrains to model diets is highly controversial. In essence, it is like lumping concepts in fair trade, sustainable food chains, vegetarian/vegan/ carnivore/ religious beliefs into a simple set of mathematical limits. Can it be done? yes, but the richness of these topics is unavoidably simplified in a mathematical model, to the point of  becoming a meaningless exercise.

For example, How do we assess some foods  as more sustainable than others? True sustainable foods  are not only judged in terms of their production footprint: it is also about distribution, manufacturing, marketing AND consumption. And distribution includes transport, storage, packaging and trading of foods. Therefore, it is not just a matter of saying that meat is more polluting than fruit and vegetables.

Likewise,  social equity does not only refer to consumers, it also refers to producers. Unfortunately, the draft report uses a number of cliches about social and environmental factors to establish the constrains in their model.

The Australian published an article on July 21 2010, suggesting that  the CSIRO and the National Heart Foundation were against the idea of including environmental drivers as an argument to limit the meat, fish and dairy intake in normal diets.

The Australian’s note refers to the submissions of both CSIRO and the Heart Foundation to the draft; I was not able to read those submissions myself, and neither the general public will be able to access them until the final report is released. Not surprisingly, the Australian Food and Grocery Council are also against the idea of using environmental drivers to suggest national diet guidelines.

Do I think that the model used in the NHMRC draft report was correct? No. I think it oversimplified very complex issues beyond what needed to be assumed in order to provide credible answers.

But I do think that there is a need to debate the effect of consumers’ food choices and environmental impacts. A good argument supporting this vision is given by Dr Rosemary Stanton in her Crikey article published yesterday. And I certainly think that we should acknowledge the social, political and environmental forces that make recommended national diet guidelines impossible to achieve for some parts of the population. I think this debate is extremely important.

A healthy diet is determined only by the effect of nutrients ingested in the human body. This ideal is what should set the vision of any dietary recommendations for a nation. Yet, when we choose the foods we eat, we are all subjected to social, cultural and environmental constrains. These constrained choices may undermine or benefit our health, our environment, our communities and our world. It is this effect that needs to be investigated.  I am an adamant advocate of this holistic vision of food chains.

For those interested in the presentations of this conference, they are available at the IOR website.

All these presentations discuss how activities to preserve perishable foods (i.e. cold chain) affect the environment and how the food industry can decrease this impact.

These include:

• Introduction from R Heap, Conference Chairman ICCCUK.
• Welcome from X Meignien, Deputy Director IIR.
• Keynote presentation from J Guilpart, Former Head of Refrigeration Processes Engineering Research Unit of Cemagref.  The presentation focuses on research that pinpoints weaknesses and strengths in the French cold chain.
• Keynote presentation from D Cleland, Head of the School of Engineering and Advanced Technology, Massey University. This presentation provides an excellent overview of the issues and challenges for the industry, including statistics and analysis of cold chain impacts.
• Mathematical modelling short course presentations from D Cleland, A Foster, A Geeraerd, B Nicolai
• Temperature control and energy efficiency in the cold chain presentations from S Estrada-Flores, D Cleland, J Evans, S James, D Pearson
• Alternative technologies review, G Maidment Professor of Mechanical Engineering London South Bank University
• Closing paper from A Pearson, President Institute of Refrigeration

It is always interesting to see how different people can interpret the same information in very different ways. After reading the article by Lucy Knight on research decline and loss of productivity in Australia, I was interested to read the book “The shifting patterns of agricultural production and productivity worldwide”. The editors of this book are J.M. Alston (University of California, Davies), B. A. Babcock (Iowa State University) and P. G. Pardey (University of Minnessotta). They were mostly interested in investigating the evidence of a potential slow down in food production, worldwide.

The evidence investigated is varied and includes data from Australia, New Zealand, the United Kingdom, the United States, China, Central and Eastern Europe, Indonesia, South Africa and Argentina.

Ms Knight interpreted the information on this book as “consistent evidence” of an “economically significant slowdown in agricultural productivity growth in most of the world since 1990“, with  important exceptions such as  China and Latin America.In this chapter, “the authors speculate that an earlier slowdown in agricultural research and development (R&D) spending growth might have contributed to the recent slowdown in productivity growth”.

But Ms Knight  quotes the conclusions of Chapter 3 only, before the evidence of the list of countries abovementioned are analysed.

The evidence of Chapter 5, which deals with Australia and New Zealand data, shows two seemingly contradictory results for agricultural productivity. Data from the Australian Bureau of Statistics (ABS) shows that over the period 1986-2006, agricultural productivity grew by 3% per year, which was 2.5 times faster than the rate of growth for the market economy as a whole. There is no evidence of a slowdown in this data, which uses national income accounting measures. A similar analysis of New Zealand for the period 1927-2001 shows an average increase of 1.8% in MFP.

Dr John Denis Mullen, who authored Chapter 5 and is an adjunct professor at Charles Sturt University and at the University of Sydney, also investigated gross measures from ABARE farm surveys. These measures only encompass broadacre agriculture –that is, grazing, cropping and dairying. These show a slowdown in productivity growth.

This is where the word seemingly comes into play: while productivity itself did grow during 1978-2007 at a rate of 1.5% annually, the rate of growth stalled. Agriculture is growing, but the pace of this growth has slowed down in the past 10 years. It is unclear what are the underlying reasons for decreasing productivity growth rates, with possible explanations including weather patterns, climate change and the decrease in R&D funding for agriculture in Australia.

It is also relevant to separate effects: productivity growth is occurring at a faster rate in WA and SA than in NSW and VIC. Also, the slowdown in productivity growth is more pronounced for cropping than for beef and sheep.

It is a pity that these studies do not encompass horticulture: I could not find a study that measures productivity for fruit and vegetable growers in Australia (if you know of any, could you please let me know?).

In horticulture, it is hard to draw conclusions from field productivity alone: for example, while there are indications of an increase in vegetable yields in products such as carrots, celery and potato, the yields for beans, green peas, cucumbers and lettuce seem to have a negative trend for the period 1996-2004.

Fruit and vegetables are an interesting case because imports of these products are increasing: 20.4% of the total fruit and vegetable consumed in Australia is imported. Breaking this percentage down, 30% and 4.2% of all processed and fresh fruit and vegetables, respectively, are imported.

Also, the role of glasshouse production in Australian horticultural productivity is not well researched.

The second critical report reviewing the leaking of about 1,000 e-mails from the Climatic Research Unit (CRU) of the University of East Anglia and any consequences to the validity of the IPCC conclusions on climate change was made public yesterday.

The main conclusions of the report were:

• On the specific allegations made against the behaviour of CRU scientists, the report found that their rigour and honesty as scientists are not in doubt.
• The report did not find any evidence of behaviour that might undermine the conclusions of the IPCC assessments.
• The report did find that there has been a consistent pattern of failing to display the proper degree of openness.

Other conclusions of the report refer to the lack of discussion about the uncertainty of the data and the lack of a proper peer review process. This was also noted in the Dutch report that I discussed yesterday.

A very interesting point raised by the Muir report was the challenges that unmoderated blogs (such as this one!) are posing to scientists and the need to come up with ways to communicate with bloggers and the community in general. The issue of providing a public space where scientists and others can debate openly was also  raised.

Another point made in the report is the need to be clear about research sponsorship. This  is an important topic here in Australia, as the media starts to question the involvement of CSIRO with resources companies.

A newly released study (that can be accessed here) by the PBL Netherlands Environmental Assessment Agency has found no errors that would undermine the main conclusions in the 2007 report of the Intergovernmental Panel on Climate Change (IPCC) on possible future regional impacts of climate change.

However,  the foundations for the summary statements should have been made more transparent. The PBL believes that the IPCC should invest more in quality control in order to prevent mistakes and shortcomings, to the extent possible.

The newspapers today  report that the IPCC’s report is “one sided”. However, they fail to state that no significant errors were found in the summary conclusions. These conclusions include projections of climate-change impacts on food, water, ecosystems, coastal regions and health, for all the earth’s continents.

Significant errors found were:

• Statements on the melting of the Himalayan glaciers and about the Dutch land area below sea level.
• The statement about a 50 to 60% decrease in productivity in anchovy fisheries on the African west coast - the review found that this was projected on the basis of erroneous interpretation of the literature.
• The statement about how many of the additional heat-related deaths projected for Australian cities are actually attributable to climate change – a sizeable fraction is due to demographic changes alone.

The Dutch review also criticises the heavy handed use of negative examples in the IPCCs summary and the lack of a statement about uncertainty. The rationale used by IPCC in selecting the worst case scenarios is that these the most relevant results to policy makers.

This is a topic that I find interesting. We, as human beings, don’t like uncertainty. We find it hard to grasp, hard to explain and hard to use. We like to see the world in a mechanistic way, where there is only one correct answer to most things. The truth is: it is all about possibilities. It is all about scenarios. All those who were trained as scientists, as I was, know that uncertainty can make a huge difference in the  physical and mathematical models we develop to explain how the world operates. But we often fail to ascertain these uncertainties, through well-planned sensitivity analyses of how variables  can affect outcomes.

I was myself trained as a mechanistic, first-principle thinker. But more and more, I am starting to realise that a mechanistic view does not offer all the answers. Which is why I am starting to think in “scenarios” terms and the use of probabilities to explain how things work. The sensible use of stochastic analyses when uncertainty is simply too high in several variables can offer several advantages, including avoiding criticisms such as the “one-sided” comment from the PBL review. Stochastic methods present the “whole story”, good and bad. Supported by probabilities,  decision makers can make an informed decision on cost-benefits of action or inaction.

Another thing that comes to mind is the extremely important role of reviewers and good quality control in the science process. The review of reports, articles and other scientific communications is often seen as a secondary activity of researchers. But it is in the review of others work that important contributions are made and errors are discovered.

More and more, pressures that minimise the reviewing effort are decreasing the times available for a thorough review process. There is pressure to review the work in short deadlines and short budgets. Reviewers have to put time aside for an activity that is not rewarded and often, not recognised enough.  Egos get on the way, as do political and social pressures.

As someone that has worked in a review system for a long time, I am aware of the pains of this process for both authors and reviewers. Writing a scientific article or a report is challenging as is. Hearing from a reviewer that we have to do more work, with other projects waiting and financial pressures mounting, is often disheartening. In my case, when I start working on the comments, as I rethink and rewrite paragraphs, I am thankful to the reviewers and I always find at the end of the review that my reports have improved significantly upon the original version.

At the end of the day, we as authors want to put something that contributes to the world.  We want to write articles, reports and statements that are correct, complete and provide answers. And more often than not, results that provoke more questions. So I take the IPCC work as part of those arguments needed for all of us to review, criticise and build upon.

Having said that, I am hoping that the IPCC realises that an open process of review, where their work is put on the table for other researchers to read and comment and improve before a final version gets out, may provide a better outcome than the closed process they use at the moment.